Bernardus J. Van Sorge disclosed a catalyst for the preparation of ortho-alkylated phenols of U.S. Pat. No. 3,972,836 in which the catalyst is made by blending mixture of magnesium oxide and a manganese oxide with about an equal amount of water, molding the blend to shape, drying the shaped blend, and heating at the calcination temperature to form the catalyst. Van Sorge also disclosed a preparation of ortho-alkylated phenols in his U.S. Pat. No. 3,974,229 by conducting the alkylation reaction in the presence of a catalyst prepared by physically blending a mixture of magnesium oxide with 1-15% by weight of manganese oxide with water, molding and heating to form the catalyst. Hence, the two patents disclosed by Van Sorge are substantially the same for teaching the preparation of a catalyst adapted for preparing ortho-alkylated phenols by blending magnesium oxide and manganese oxide, which however still results in a poor yield of 2,6-dimethyl phenol, for instance, the 2,6-xylenol distribution (wt. %) being only 50.2% when the reaction is performed at a temperature of 480.degree. C. for 400 hours as shown in Example 3 (Run 3a), showing an activity of the catalyst being not so satisfactory.
The present inventors have found the drawback of Van Sorge's process and invented the present process for preparing a catalyst for ortho-alkylation of a phenol compound by improving the catalyst activity and product yield over the Van Sorge's process.